Differences in airborne stability of SARS-CoV-2 variants of concern is impacted by alkalinity of surrogates of respiratory aerosol

Journal of The Royal Society Interface, Journal Year: 2023, Volume and Issue: 20(203)

Published: June 1, 2023

The mechanistic factors hypothesized to be key drivers for the loss of infectivity viruses in aerosol phase often remain speculative. Using a next-generation bioaerosol technology, we report measurements aero-stability several SARS-CoV-2 variants concern droplets well-defined size and composition at high (90%) low (40%) relative humidity (RH) upwards 40 min. When compared with ancestral virus, Delta variant displayed different decay profiles. At RH, viral approximately 55% was observed over initial 5 s both variants. Regardless RH variant, greater than 95% lost after min being aerosolized. Aero-stability correlate their sensitivities alkaline pH. Removal all acidic vapours dramatically increased rate decay, 90% 2 min, while addition nitric acid vapour improved aero-stability. Similar artificial saliva growth medium observed. A model predict is proposed: pH exhaled drives loss; salt content limits infectivity.

Language: Английский

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Block the Spread: Barriers to Transmission of Influenza Viruses

Annual Review of Virology, Journal Year: 2023, Volume and Issue: 10(1), P. 347 - 370

Published: June 12, 2023

Respiratory viruses, such as influenza cause significant morbidity and mortality worldwide through seasonal epidemics sporadic pandemics. Influenza viruses transmit multiple modes including contact (either direct or a contaminated surface) inhalation of expelled aerosols. Successful human to transmission requires an infected donor who expels virus into the environment, susceptible recipient, persistence within environment. The relative efficiency each mode can be altered by viral features, environmental parameters, recipient host characteristics, persistence. Interventions mitigate target any these factors. In this review, we discuss many aspects transmission, systems study it, well impact natural barriers various nonpharmaceutical pharmaceutical interventions.

Language: Английский

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Antimicrobial efficacy, mode of action and in vivo use of hypochlorous acid (HOCl) for prevention or therapeutic support of infections.

PubMed, Journal Year: 2023, Volume and Issue: 18, P. Doc07 - Doc07

Published: Jan. 1, 2023

The objective is to provide a comprehensive overview of the rapidly developing field current state research on in vivo use hypochlorous acid (HOCl) aid infection prevention and control, including naso-pharyngeal, alveolar, topical, systemic HOCl applications. Also, examples are provided dedicated applications COVID-19. A brief background HOCl's biological chemical specifics its physiological role innate immune system understand effect context body's own defense mechanisms.Es wird ein umfassender Überblick über den aktuellen Stand der Forschung zum In-vivo-Einsatz von hypochloriger Säure zur Infektionsprävention und -bekämpfung gegeben. Der Schwerpunkt liegt auf nasalen, alveolären topischen Anwendungen. Außerdem werden Beispiele für spezielle Anwendungen bei COVID-19 vorgestellt. Um die Wirkung im Zusammenwirken mit körpereigenen physiologischen Abwehrmechanismen zu verstehen, biologischen chemischen Besonderheiten seiner Rolle humanen Immunsystem erläutert.

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Review of factors affecting virus inactivation in aerosols and droplets

Journal of The Royal Society Interface, Journal Year: 2024, Volume and Issue: 21(215)

Published: June 1, 2024

The inactivation of viruses in aerosol particles (aerosols) and droplets depends on many factors, but the precise mechanisms are not known. system involves complex physical biochemical interactions. We reviewed literature to establish current knowledge about these identify gaps. identified 168 relevant papers grouped results by following factors: virus type structure, or droplet size, temperature, relative humidity (RH) evaporation, chemical composition droplet, pH atmospheric composition. These factors influence dynamic microenvironment surrounding a virion thus may affect its inactivation. Results indicate that experience biphasic decay as carrier aerosols undergo evaporation equilibrate with air, their final state (liquid, semi-solid solid) RH. Virus stability, RH temperature interrelated, effects multifaceted still completely understood. Studies impact stability have raised new questions require further exploration. frequent practice studying large culture media limit our understanding for transmission, so we encourage use physiologically size future research.

Language: Английский

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The microphysics of surrogates of exhaled aerosols from the upper respiratory tract

Aerosol Science and Technology, Journal Year: 2024, Volume and Issue: 58(4), P. 461 - 474

Published: Jan. 17, 2024

Airborne transmission plays a significant role in the of respiratory diseases such as COVID-19, for which aerosol droplets are responsible transportation potentially infectious pathogens. However, physicochemical dynamics during exhalation process not well understood. The representativeness droplet surrogates exhaled and suspension media aerosols currently used laboratory studies remains debated. Here, we compare evaporation kinetics equilibrium thermodynamics surrogate including sodium chloride, artificial saliva (AS) Dulbecco's modified Eagle's medium (DMEM) by using Comparative Kinetics Electrodynamic Balance. potential influences composition on hygroscopic response phase behavior, influence mucin reported. hygroscopicity measurement was to verify benchmark prediction complex solutions Single Aerosol Particle Drying Trajectory model. We show that compositionally culture differs from chloride (mucin-free solutions). DMEM contained three distinctive phases when drying at range humidities, semi-dissolved evaporating environmental humidity range. effect behavior low RH were compared between AS solutions. In both cases, delayed crystallization time droplets, but it promoted change (from homogenous semi-dissolved/spherical with inclusions) occur higher water activities.

Language: Английский

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Toward Standardized Aerovirology: A Critical Review of Existing Results and Methodologies

Environmental Science & Technology, Journal Year: 2024, Volume and Issue: 58(8), P. 3595 - 3608

Published: Feb. 14, 2024

Understanding the airborne survival of viruses is important for public health and epidemiological modeling potentially to develop mitigation strategies minimize transmission pathogens. Laboratory experiments typically involve investigating effects environmental parameters on viability or infectivity a target virus. However, conflicting results among studies are common. Herein, 34 aerovirology were compared identify links between compositional viruses. While specific experimental apparatus was not factor in variability reported results, it determined that procedure major contributed discrepancies results. The most significant contributor poorly defined initial viable virus concentration aerosol phase, causing many measure rapid inactivation, which occurs quickly after particle generation, leading Consistently, measured their reference minutes aerosolization higher at subsequent times, indicates there an loss captured these studies. composition particles carry also found be viruses; however, mechanisms this effect unknown. Temperature aerosol-phase viability, but lack directly compare temperature phase bulk phase. There need repeated measurements different research groups under identical conditions both assess degree attempt better understand already published data. Lack standardization has hindered ability quantify differences studies, we provide recommendations future These as follows: measuring using "direct method"; use equipment maximizes time resolution; all losses appropriately; perform, least, 5- 10-min sample, if possible; report clearly suspension; gas throughout experiment. Implementing will address oversights existing literature produce data can more easily quantitatively compared.

Language: Английский

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Size-Resolved Elemental Composition of Respiratory Particles in Three Healthy Subjects

Environmental Science & Technology Letters, Journal Year: 2023, Volume and Issue: 10(4), P. 356 - 362

Published: March 24, 2023

The chemical composition of respiratory particles is interest because the viability any viruses and bacteria in has been shown to depend on this factor. Using computer controlled scanning electron microscopy/energy dispersive X-ray spectroscopy (CCSEM/EDX), we analyzed size-resolved greater than 35,000 individual collected from three healthy human subjects, quantitatively at nanometer-scale spatial resolution. desiccated ranged size 0.05 4.4 μm, mode distribution was approximately 0.1 μm. Particles were heterogeneous composition, with 42% them containing a carbon atomic percentage 95% 53% Na + P K Cl 5%. Based particles' elemental classified into five categories: 48%–56% total number carbonaceous, mostly organic; 40%–50% Na-rich salt; 0.3%–0.5% P-rich 0.1–0.8% K-rich 1%–2.5% mixed salt. ratio salt carbonaceous increased increasing particle size; larger 2 μm dominated by Size-dependent differences may have important implications for efficiency airborne transmission pathogens.

Language: Английский

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Indoor air humidity revisited: Impact on acute symptoms, work productivity, and risk of influenza and COVID-19 infection

International Journal of Hygiene and Environmental Health, Journal Year: 2023, Volume and Issue: 256, P. 114313 - 114313

Published: Dec. 27, 2023

Recent epidemiological and experimental findings reconfirm that low indoor air humidity (dry air) increases the prevalence of acute eye airway symptoms in offices, result lower mucociliary clearance airways, less efficient immune defense, deteriorate work productivity. New research also support environmental conditions for risk infection influenza COVID-19 virus is lowest Goldilocks zone 40–60% relative (RH) by decrease airways' susceptibility, which can be elevated particle exposure. Furthermore, RH generation infectious laden aerosols exhaled from infected people. In general, elevation dry health airways concomitantly with viability virus. Thus, negative effects ventilation outdoor (low absolute humidity) should assessed according to 1) weakened functionality 2) increased possible transmissibility virus, 3) evaporation containing droplets out droplet nuclei (also at high room temperature), their floating time air. The removal acid-containing ambient filtration pH, viruses, infection, synergistically may further increase dilution pollutants compared beneficial control center RH, an essential factor optimal additional positive impact on symptoms, productivity, reduced infection.

Language: Английский

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The aerobiological pathway of natural respiratory viral aerosols

TrAC Trends in Analytical Chemistry, Journal Year: 2024, Volume and Issue: 172, P. 117557 - 117557

Published: Jan. 23, 2024

Aerosols generated from the human respiratory tract containing infectious virus can be challenging to measure due a number of factors that impact infectivity they contain. These include limitations in understanding aerosol composition, chemical processes change composition and infectivity, effects collection process. The aerobiological pathway represents framework understand how influencing these particles collectively contribute overall their potential infectiousness. Here, is used highlight areas research could improve natural viral hazards. In particular, an improved required biological phase composition. findings will also invaluable airborne detection.

Language: Английский

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Quantifying Contributions of Factors and Their Interactions to Aerosol Acidity with a Multiple-Linear-Regression-Based Framework: A Case Study in the Pearl River Delta, China

Atmosphere, Journal Year: 2024, Volume and Issue: 15(2), P. 172 - 172

Published: Jan. 29, 2024

This study presents an approach using multiple linear regression to quantify the impact of meteorological parameters and chemical species on aerosol pH variance in urban setting Pearl River Delta, China. Additionally, it assesses contributions interactions among these factors pH. The analysis successfully explains over 96% variance, attributing 85.8% original variables 6.7% bivariate interactions, with further 2.3% 1.0% from trivariate quadrivariate respectively. Our results highlight that factors, particularly temperature humidity, are more influential than components affecting variance. Temperature alone accounts for 37.3% while humidity contributes approximately 20%. On front, sulfate ammonium most significant contributors, adding 14.3% 9.1% In realm interplay between components, especially TNO3–RH pair, is exceptionally impactful, constituting 58.1% total contribution interactions. summary, this illuminates their interplay, suggesting integration statistical methods thermodynamic models enhanced understanding acidity dynamics future.

Language: Английский

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